By CLYDE HABERMAN,

Published: December 18, 1992

JERUSALEM, Dec. 17—
Buses filled with nearly 400 bound and blindfolded Palestinians crossed the border into Lebanon tonight as Israeli troops carried out mass expulsions ordered by the Government and sanctioned by Israel's Supreme Court after a day of legal arguments and rancor.

There had not been deportations of Palestinians on anything approaching this scale since the period soon after Israel took control of the West Bank and Gaza Strip in the 1967 Middle East War.

Handed $50 each, along with some food, jackets and blankets, the Palestinians from both the West Bank and Gaza were taken on a wintry night into the "security zone" that Israel has declared in southern Lebanon. They were then to be dropped off at the northern edge of the buffer zone and ordered into territory controlled by Lebanese forces. Lebanon Is Resistant

Lebanon, which had accepted other deported Palestinians in the past, said that this time it would close its checkpoints.

In Beirut, Lebanese security officials said heavily armed soldiers, acting on instructions from the Government, blocked roads in southern Lebanon tonight in an attempt to prevent the expelled Palestinians from entering Lebanese-controlled territory.

After the Lebanese troops had been ordered into a high state of alert, they stopped traffic at the crossing points along the northern edge of the security zone. Five Killings Cited

Prime Minister Yitzhak Rabin defended the expulsions as a necessary blow against Islamic fundamentalists who in recent days have killed four Israeli soldiers and a border policemen and who, he said, would destroy Middle East peace negotiations unless stopped.

But as Israeli officials had expected, the mass punishment produced an international human-rights outcry and warnings from Palestinian political leaders that Israel itself may have delivered a mortal blow to the peace talks, which they boycotted in Washington today as the latest round staggered fruitlessly to a close.

In Tunis, the Palestine Liberation Organization said talks with Israel would be suspended until the deported people were allowed back home.

Human-rights groups like Amnesty International and some foreign governments, including Britain speaking in behalf of the European Community, had appealed to Israel not to follow through on the ordered expulsions, saying the Fourth Geneva Convention of 1949 prohibits this sort of forced transfer from occupied territories.

The State Department said in Washington that the United States "strongly condemns the action of deportation." Marlin Fitzwater, President Bush's spokesman, asked countries in the Middle East to "form a concerted voice calling for an end to all forms of violence, and avoid reactions such as deportations that risk complicating the search for peace." U.N. Asks Reversal

At the United Nations, Secretary General Boutros Boutros-Ghali asked Israel to rescind the expulsion orders and allow the Palestinians to return to the territories.

Even some of the 16 Cabinet ministers who had approved the deportations on Wednesday -- unanimously with the exception of Justice Minister David Libai, who abstained -- acknowledged that they were not entirely comfortable with their vote. Most of them were left-of-center politicians who had spent years in the opposition and who had protested when previous Governments expelled Palestinians -- until today a total of 66 since the start of the anti-Israel uprising in December 1987.

Suddenly, in one shot, they themselves had increased the total seven-fold.

But they had no choice, they said. Israel, they argued, had to strike hard, especially against the militant fundamentalist group Hamas, which is unalterably opposed to the peace talks and which has taken responsibility for the recent spate of killings, which left many Israelis shocked and hungry for revenge. Possible alternatives to expulsions included house demolitions and looser open-fire regulations for soldiers, they said. Decision 'Wasn't Easy'

"I have a legal problem with the decision that the Government has taken," said Energy Minister Amnon Rubinstein, a leader of the leftist Meretz bloc. But he added: "My duty is not to criticize but to choose from three major alternatives: do nothing, do this or do something worse. I decided to vote for this. It wasn't easy."

For his part, Mr. Rabin, architect of an iron-fist policy against Palestinian rioters when he was Defense Minister five years ago, said he had to act against "an escalation of murderous terrorist activity" by Hamas and another group, Islamic Holy War. To do nothing after the latest fatal attacks on Israelis would have risked making Israel look weak and would have further strengthened Hamas, he argued.

Besides, the Prime Minister said, the expulsions, described by the Government as "temporary removal orders," are not permanent. They are to last no more than two years and can be appealed in absentia -- "a temporary distancing of inciters and accomplices of inciters to heinous murders," Mr. Rabin said.

It was doubtful, however, that Israel was about to put an end to violence by getting rid of these particular Palestinians, whose number was tentatively put at 383. Held Bound for Day